PREBIOTIC FOOD INGREDIENTS CONFER PHYSIOLOGICAL BENEFITS TO HUMANS BY THE MODULATION OF GUT MICROBIOTA, WHICH LEADS TO BENEFITS SUCH AS THE ALLEVIATION OF METABOLIC DERANGEMENTS DUE TO DISEASE STATES SUCH AS OBESITY AND TYPE-2 DIABETES. WE HAVE DEVELOPED A METHOD USING CONTINUOUS EXTRUSION TO PRODUCE NONDIGESTIBLE OLIGOSACCHARIDES FROM SUGARS, SUCH AS LOW-COST LACTOSE, WHICH WE CALL POLYLACTOSE. IN PREVIOUS WORK, WE HAVE DEMONSTRATED THAT POLYLACTOSE INCREASES THE ABUNDANCE OF LACTOBACILLUS AND BIFIDOBACTERIA IN THE LARGE INTESTINE OF RATS, AS WELL AS REDUCES ADIPOSITY AND LIVER LIPIDS. HERE, WE PROPOSE TO REPLICATE AND EXTEND OUR PREVIOUS FINDINGS. FIRST, WE WILL PRODUCE OLIGOSACCHARIDES USING 4 DIFFERENT LACTOSE AND GLUCOSE CONCENTRATIONS RANGING FROM 100% LACTOSE TO 100% GLUCOSE (POLYDEXTROSE). THESE WILL BE CHARACTERIZED FOR THEIR SUGAR COMPOSITION AND DEGREE OF POLYMERIZATION. SECOND, OUR EXTRUDED OLIGOSACCHARIDES, COMMERCIALLY PRODUCED POLYDEXTROSE, ANDGALACTOOLIGOSACCHARIDES WILL BE FED TO DIET-INDUCED OBESE RATS TO EVALUATE THE EFFECT OF THESE OLIGOSACCHARIDES ON GLYCEMIC CONTROL, ADIPOSITY, LIVER LIPIDS, AND METABOLIC CHANGES IN ADIPOSE TISSUE. FINALLY, A MICROBIOME ANALYSIS OF THE LARGE INTESTINAL CONTENTS FROM THE RATS WILL BE CONDUCTED TO ASCERTAIN THE EFFECT OF THE DIFFERENT OLIGOSACCHARIDES ON THE RELATIVE ABUNDANCE OF THE MICROFLORA. THIS STUDY, IF POSITIVE, WILL CONFIRM THAT POLYLACTOSE IS A PREBIOTIC, WILL REVEAL INFORMATION ABOUT ITS MECHANISM OF ACTION FOR REDUCING ADIPOSITY, AND WILL PROVIDE THE JUSTIFICATION FOR A HUMAN TRIAL OF POLYLACTOSE FEEDING. IF POLYLACTOSE IS DEMONSTRATED TO BE A POTENT PREBIOTIC, IT WOULD BE AN ECONOMICAL DIETARY INGREDIENT TO IMPROVE THE DIGESTIVE HEALTH OF AMERICANS.